Liquid electro-photographic (LEP) printing uses a special kind of ink to form images on paper or other printable media. The LEP printing process involves placing an electrostatic charge pattern of the desired printed image on a photoconductor and developing the image by applying a thin layer of ink to the charged photoconductor. Charged particles in the ink cause the ink to adhere to the pattern of the desired image on the photoconductor. The ink pattern is transferred from the photoconductor to an intermediate transfer member and then from the intermediate transfer member to the paper. Ink is applied to the photoconductor with a “developer” roller. The developer roller is part of a unit with rollers and electrodes that use electric fields to form an ink layer on the developer roller which is then transferred to the photoconductor. Voltage is applied to each of the rotating rollers through a contact to stationary elements in the unit that are connected to a power supply.
The same part numbers designate the same or similar parts throughout the figures.